1. Field of the Invention
The present invention relates to an electronic-data distribution system capable of distributing electronic data to a personal computer or the like required to be sent the electronic data while dispersing a load on a distribution server caused by the electronic-data distribution.
2. Description of the Related Art
In recent years, a variety of work such as document composition at an office or the like has been performed using an information device such as a PC (personal computer), and specifically, using a program installed in a PC or the like.
A program is frequently modified for an improvement or the like, and if modified, an operator needs to acquire the modified program and install it in a PC or the like. The program acquisition and installation is burdensome to the operator, and thus, there are known various arts of lightening such a work load.
For example, in order to lighten a work load imposed on the operator of a PC or the like when acquiring the modified program, a program distribution server is generally provided which distributes the modified program to a PC or the like over a network.
When the program distribution server distributes the modified program to a PC or the like, however, a load borne on the program distribution server and the network is known to be heavier as the number of PCs increases. Particularly, the recent Internet development prompts more and more distribution servers to distribute not only programs but also files, music data or the like (below generically called “electronic data”) to a PC or the like, thereby greatly requiring that a load caused by the distribution should be dispersed.
In order to solve the problem, Japanese Patent Laid-Open Publication No. 9-231086 offers an art of managing the frequency in use of programs in a PC or the like and requesting a program distribution server to distribute only programs used with higher frequency after modified.
However, if the modified programs are, for example, electronic data involved in security or the like such as virus vaccine software and a virus pattern file, then the electronic data after modified needs distributing regardless of the height of frequency in use. Hence, the art according to Japanese Patent Laid-Open Publication No. 9-231086 cannot be applied to the electronic data which must be distributed.